The invention includes a system to push collected liquid from below a heat exchanger to a remote location.
A heat exchanger may be a device used to transfer heat from a fluid on one side of a barrier to a fluid on the other side without bringing the fluids into direct contact. A heat exchanger system may include a coiled set of heat exchanging pipes and chilled coolant. Air conditioners, refrigerators, and freezers and dehumidifiers conventionally employ a heat exchanger system to remove heat from air that is local to the system. This heat eventually is transported to a remote location for disposal.
In operation, the chilled coolant of the heat exchanger system is circulated within the interior of the pipes to cool the exterior surface of the pipes. While the chilled coolant is circulated within the pipes, air from the local atmosphere is drawn over the exterior surface of the pipes. The cooled pipe exterior surfaces draw heat from the air so as to cool the air and heat the circulating coolant. As the heat exchanging process continues, the temperature of the local air decreases.
Atmospheric air includes nitrogen and oxygen as well as varying amounts of moisture. Thus, a side effect of drawing heat from the air at the surface of the pipes is that atmospheric moisture condenses on the heat exchanger pipes as condensate. This condensate builds on the pipes over time and eventually drips as water into a pan located below the heat exchanger pipes. The water collects as a pool in the pan.
The collected water is not supposed to evaporate back into the air. In some applications, the heat exchanging process results in more collected water than the pan can hold. For example, air conditioning systems condense much more water than can be stored. Here, it is desirable that this water be mechanically removed from the pan before the water fills the pan.
In a window based, saddle air conditioning system, the saddle air conditioner is hung over the bottom rail of a window sill so that the air cooling unit is located within a room and the heat discharging unit is located outside. Removing water from the pan of the air cooling unit may involve raising the pooled water up from the pan and over the bottom rail of a window sill. Conventionally, a water pump is used to remove the water from the pan and pass the water over the window sill. However, a water pump is noisy, bulky, and requires a relatively large amount of power to operate. When operating, the water pump causes vibrations throughout the air conditioner that, in turn, cause noise to emanate from the air cooling unit into the room. It is desirable to minimize these problems.
The invention includes a liquid pump system, and in the preferred embodiment, a condensate pumping system. The condensate pumping system may include a tank having an upper reservoir and a sump disposed below the upper reservoir. The upper reservoir may include an orifice and may be positioned to receive condensate from a set of evaporator coils. The condensate pumping system may also include a device to seal the orifice, a condensate tube connected to the sump, and an air pump attached to the sump through an air tube.